Propulsion and steering device for watercrafts



Jan. 17, 1967 F, w. PLEUGER ETAL 3,293,349

PROPULSION AND'STEERING DEVICE'. FOR WATERCRAFTS Filed June 15, 1965 United States Patent O 3,298,349 PRQPULSION AND STEERING DEVICE FOR WATERCRAFTS Friedrich Wilhelm Pleuger, .uthornstrasse 80, and Johann Schneider, Zitzewitzstrasse 10, both of Hamburg- Wandsbek, Germany Filed June 15, 1965, Ser. No. 464,081 Claims priority, application Germany, July 7, 1964, P 34,643 4 Claims. (Cl. 11S- 18) This invention relates to a propulsion and steering device for watercrafts, and more particularly to an outboard driving device with an electric motor, which is primarily used for ferry boats, floating cranes or drilling platforms, tankers, salvaging and similar vessels and especially for operation of tire-endangered environment.

It is an object of the invention to provide a propulsion and steering device which in comparison to its performance is of small dimensions and of a structure enabling it to take up a minimum of space on the deck of the vessel.

Another object is to construct the propulsion device in such a manner that it is fully protected against any explosions and may be safely operated in lire-endangered environments, for instance on tankers, floating `oil drilling platforms, salvaging or fire extinguishing crafts.

Still another object of the invention is to render the electric propulsion device absolutely safe against danger of fire, and this also if any damages within the driving motor should arise.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction With the accompanying drawings wherein, by way of example,

FIG. 1 is an elevational and partly sectional view of an embodiment of the invention;

FIG. 2 is a cross section of its pipes of cables and hoses.

Briey stated, the invention is related to an electric outboard propulsion and steering device which may be fastened to the vessel at any points required for its operation. An electric motor with a vertical shaft, which drives the propeller through the conventional gear train, has a closed casing filled with water, which casing is surrounded by a casing shell sealed against the water filling of the motor and having cooling water running through it. By this structure, the heat which is generated within the electric motor is transmitted, via the inside Water filling of the motor, straightly to the cooling water current and together with this is removed to the outside. Because of the cooling intensity, the motor can take heavy electric charges so that it may be of small and thin shape and yet is of high eiiiciency. It is advantageous that the electric motor form part of the vertical driving shaft and be arranged underneath the upper bearing of the driving shaft. By this construction, the motor does not claim any deck space, and the given space in general is utilized in a good manner. The motor preferably is rotatable around a vertical axle which is fastened to a bracket which in itself is swingable around a horizontal axle mounted on the vessel. Only the electricity supply cables and cooling water pipes lead from the electric motor, or, in devices with a plurality of motors, from the single electric motors to the main engine room in the interior of the vessel so that the deck does not have to take up any driving elements.

Referring now to FIG. 1 of the drawings, the pontoonshaped watercraft 1, which is, for instance, designed as a oating crane, is provided with a plurality of propulsion aggregates, of which only one is shown in the drawing. The propulsion aggregate consists of a propeller 2 ICC the horizontal shaft of which, via a bevel gear 3, co-

operates in a conventional manner with the vertical driving shaft 4. The upper end of driving shaft 4 is coupled with the squirrel cage rotor 5 of an electric motor 6, the slim cylindrical casing 7 of which has a liquid-tight sealing and is filled with a liquid, such as pure water.

The bevel gear 3 and driving shaft 4 are enclosed by a casing 8 the upper part of which is developed into a shell 9 and is terminated in a socket 10. Socket 10 is mounted in a bearing ring 11, which is carried by the lower arm of a bracket 12. Bracket 12 is swingable around a horizontal pivot 13 by which it is connected with the hull of the vessel. At its upper arm, bracket 12 carries a bearing ring 14, in which the upper end of a casing shell 16, being shaped as a socket 15, is rotatably mounted. A guiding or steering arm 18 terminating in a gripping handle 17 co-operates with a socket 15 and enables the whole propulsion aggregate with its propeller 2 to be swung around a lvertical axle for steering the vessel.

Together with motor casing 7, casing shell 16 forms an annular channel 19 for admittance of a cooling liquid, such as water, which is supplied by a hose 20 connected to the upper end of casing shell 16 and removed by another hose 21. A third hose 22 leads to the interior of electric motor 6 and is lled `with pure water. The water lling the motor 6 is under higher hydrostatic pressure than the cooling water in annular channel 19. Also connected to motor 6 is the electric current supply cable 23.

As illustrated in FIG. 2, the electric current `supply cable 23, which may, for instance, be provided with three conductors 24, and which supplies electric motor 6 with three-phase alternating current, extends centrally around hose 22 conveying the pure water to motor casing 7, and is enclosed by the hoses 20 and 21 serving for supply and removal of the cooling water for the annular channel 19. This construction results in a particularly space-saving arrangement which at the same time is of good working reliability as the water currents inside and around the electricity supply cable safely suppress any sparks.

The current supply cable 23 as well as the three hoses 20, 21, 22 lead to the central engine room of the vessel. Apart from these, there are no parts of the propulsion device to claim any space on deck of the vessel.

In case the electric motor 6 suffers an electric damage the water lling inside the motor and the cooling water contained in annular channel 19 have the effect of a fire extinguishing water supply which is available at the very point of danger, and the flow of cooling water continuously delivered by hose 20 is an additional fire extinguishing supply. The pure water filling of motor casing 7 is separated from the cooling water circulation ofchannel 19 and is held under a precalculated static overpressure so that any leakage can be signalized by the sinking hydrostatic pressure. Alternatively, one may employ sea or river Water to ow through the annular channel 19, and it may ow directly down the casing shell 16, in which case the hose 21 for removal of cooling water is left out. The hydrostatic pressure of the water within motor casing 7 is preferably kept at a higher level than the pressure of the cooling Water in annular channel 19.

The single propulsion aggregates are centrally controlled from the engine room, which enables exact maneuvering of the vessel, and which allows every single aggregate to be turned by its respective steering ar-m 18. When the vessel is towed or when the single aggregates are on repair or inspection they may be upwardly turned around the horizontal pivot 13, which causes the aggregates to be` situated above deck level and to be easily accessible.

Owing to its intense cooling, the electric motor may be of a comparatively small diameter and of a thin structure so that only little space for the propulsion aggregate is required at the sides of the hull of the vessel. Besides, the electric motor 6 is `greatly protected against damages owing to its being surrounded Iby the robust casing shell 16 and therefore oers high working reliability in spite of rough working conditions.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is illustrated in the drawing and described in the specification, but only as indicated in the accompanying claims.

What we claim is:

1. A propulsion and steering device for watercraft, comprising a propeller structure, a vertical driving shaft, a bevel gear, arranged between propeller an-d said shaft, an electric motor, having a squirrel cage rotor actuating on said driving shaft, a closed casing for said electric motor, lled with a liquid, a casing shell surrounding said motor casing and forming an annular channel together with it, means for the supply and removal of liquid to and from said annular channel, and elements for supporting sai-d motor and propeller, said elements adapted to detachably fasten the aggregate to the vessel and to turn it around a horizontal and a vertical axle, wherein an electric current supply cable and a hose for supply of pure water are connected to the motor casing and a hose for supply of cooling water for the annular channel is connected to the external casing shell, and in which said electric current supply cable concentrically extends around the water hoses.

2. The device as in claim 1, in which the electricity supply cable encloses the pure water supply hose connected to the motor casing and is enclosed by the hose for supply of cooling water to the annular channel.

3. An electric propulsion and steering device for watercraft, comprising a horizontal propeller, a vertical driving shaft, bevel ygears operatively connecting said driving shaft with said propeller, a squirrel cage rotor driving said shaft, a casing enclosing said rotor and adapte-d to be filled with a liquid, another casing spaced from and enclosing the first-mentioned casing, means supplying a cooling liquid to the space between the two casings and withdrawing sad cooling liquid from said space, whereby said space is included in a liquid cooling circuit, an upper bearing ring carried by said other casing adjacent the top thereof, a lower bearing ring carried by said other casing adjacent the bottom thereof, a bracket connected with said upper and lower 'bearing rings, and a horizontal pivot carrying said bracket.

4. A device in accordance with claim 3, wherein the liquid in the first-mentioned casing constitutes a column having a higher hydrostatic pressure than the cooling liquid supplied into said space.

References Cited by the Examiner UNITED STATES PATENTS 1,887,540 11/1932 Buchet 11S-18 2,429,774 10/1947 Schultz et al 115-18 3,135,211 6/1964 Pezzillo 310-54 3,183,384 5/1965 Flaherty et al 310-54 MILTON BUCHLER, Primary Examiner.

ANDREW H. FARRELL, Examiner. 

1. A PROPULSION AND STEERING DEVICE FOR WATERCRAFT, COMPRISING A PROPELLER STRUCTURE, A VERTICAL DRIVING SHAFT, A BEVEL GEAR, ARRANGED BETWEEN PROPELLER AND SAID SHAFT, AN ELECTRIC MOTOR, HAVING A SQUIRREL CAGE ROTOR ACTUATING ON SAID DRIVING SHAFT, A CLOSED CASING FOR SAID ELECTRIC MOTOR, FILLED WITH A LIQUID, A CASING SHELL SURROUNDING SAID MOTOR CASING AND FORMING AN ANNULAR CHANNEL TOGETHER WITH IT, MEANS FOR THE SUPPLY AND REMOVAL OF LIQUID TO AND FROM SAID ANNULAR CHANNEL, AND ELEMENTS FOR SUPPORTING SAID MOTOR AND PROPELLER, SAID ELEMENTS ADAPTED TO DETACHABLY FASTEN THE AGGREGATE TO THE VESSEL AND TO TURN IT AROUND A HORIZONTAL AND A VERTICAL AXLE, WHEREIN AN ELECTRIC CURRENT SUPPLY CABLE AND A HOSE FOR SUPPLY OF PURE WATER ARE CONNECTED TO THE MOTOR CASING AND A HOSE FOR SUPPLY OF COOLING WATER FOR THE ANNULAR CHANNEL IS CONNECTED TO THE EXTERNAL CASING SHELL, AND IN WHICH SAID ELECTRIC CURRENT SUPPLY CABLE CONCENTRICALLY EXTENDS AROUND THE WATER HOSES. 